Mexico's drug violence has claimed tens of thousands of lives and left many families without closure, unsure if their loved ones are alive or dead.

Human-rights activists say of the nearly 40,000 crimes perpetrated in the past five years, 95 per cent have never been prosecuted or investigated.

The fact that authorities have not identified most of the bodies in mass graves, coupled with the lack of information available to victims, has led many to believe that most of the bodies are ending up in unmarked graves in cemeteries.

Al Jazeera's Monica Villamizar has one family's story from Mexico City.